1. Field of the Invention
The present invention relates to a camera system comprising a camera head including an image pickup optical system and an image pickup device, and a camera main body on which the camera head is detachably attached.
2. Description of the Related Art
Instead of a conventional camera system to which an interchangeable lens is attached in an interchangeable manner to pickup an image, there is proposed a camera system comprising a camera head including an image pickup optical system and an image pickup device, and a camera main body on which the camera head is detachably attached. In such a camera system, if a display screen is provided on the side of the camera main body, the display screen can be used as the finder. If the camera head is provided with the image pickup device, a finder called EVF (Electric View Finder) can be provided on the side of the camera head using an image produced by the image pickup device.
In a single-lens reflex camera, it is absolutely necessary to provide a mirror for reflecting a subject on the side of the finder due to its structure. Therefore, there is a problem that the finder optical system is increased in size, and the entire finder is increased in size (see Japanese Patent Applications Laid-open No. 5-341356 and No. 8-82838 for example).
However, the finder of the single-lens reflex camera has a merit that a subject seen by the image pickup optical system can be recognized as it is unlike the EVF and thus, a cameraman called a high amateur having higher skills than a professional cameraman preferably use such a finder.
Makers of the camera systems desire to provide camera systems having excellent usability for all users including beginners and skilled cameramen called the high amateurs. From such a viewpoint also, it is desired that it is possible for beginners to pickup image using the display screen instead of the finder, and for the high amateurs to pickup image using the finder, while reducing the camera system in size.